Abraham Maslow's Hierarchy of Needs is a psychological theory that outlines a five-tier model of human needs, often depicted as a pyramid. The levels, from the bottom to the top, are physiological needs (like food and water), safety needs (such as security and stability), love and belonging (including relationships and social connections), esteem needs (which involve self-respect and recognition), and self-actualization (the realization of personal potential). According to Maslow, individuals must satisfy lower-level needs before they can address higher-level needs. For example, a person struggling to meet their physiological needs may find it challenging to focus on building relationships or achieving personal goals. This hierarchy helps explain how human motivation evolves as basic needs are fulfilled.